Col de Conche / Col de Braitaz

Overview

The Col de Conche, also signed as the Col de Braitaz, is a genuine hors catégorie (HC) test that demands respect from the first pedal stroke. Over 14.1 km the road climbs at an average gradient of 9.45%, lifting you from a start elevation of 389 m to a summit at 1725 m. That is 1336 m of net elevation gain, with 1286 m of total ascent packed into a climb that almost never lets up. There are no soft categories here: HC sits above 1, 2, 3 and 4, and this profile earns the label.

How the Gradient Unfolds

What makes this climb brutal is not a single wall but the consistency of the punishment. A 9.45% average over 14.1 km means the road rarely dips into anything resembling recovery. With near-zero difference between the 1336 m net gain and the 1286 m total ascent, you can read the profile plainly: this is an unbroken upward drag, not a rolling road that gives back what it takes.

The sting comes from the max gradient of 22.91% — more than double the average. Ramps like that shatter rhythm, forcing repeated surges out of the saddle before you settle back onto the relentless mid-climb pitch. Expect the steepest sections to arrive without warning and to cost you dearly if you have already overspent.

Pacing Notes

Discipline decides this climb. With an average of 9.45% for 14.1 km, effort management matters more than raw power. Anchor your pacing to your FTP: on a climb this steep and this long, riding even slightly above threshold early will hollow you out long before the summit.

If you are unsure of your threshold, run the numbers first with the FTP estimator. Aim to hold a steady, sub-threshold effort on the sustained pitches and reserve a little headroom for the 22.91% spikes — those ramps will briefly push you over threshold whether you like it or not, so bank the margin in advance rather than chasing it back.

Gearing

Do not under-gear this one. For a 14.1 km climb averaging 9.45% with a 22.91% max, most riders will want the widest range they can fit. A compact 34-tooth chainring paired with a 34×32 cassette is a sensible baseline, and on the steepest ramps you will be grateful for every tooth — stepping up to 34×34 gives you a lower bailout gear that keeps your cadence alive when the road tips past 20%.

The goal is to protect your knees and your pacing plan: spinning a slightly easier gear at a sustainable cadence beats grinding a bigger one into oxygen debt over 1336 m of climbing.

Summary

The Col de Conche / Col de Braitaz is an uncompromising HC climb: 14.1 km, a 9.45% average, and pitches to 22.91% that reward patience and punish ego. Pace to your threshold, gear low, and treat the 1336 m of vertical from 389 m to 1725 m as the long, honest effort it is.

Length: 14.1 km
Average gradient: 9.45%
Max gradient: 22.91%
Start: 389 m
Summit: 1725 m
Net gain: 1336 m
Total ascent: 1286 m
Category: HC